Edelweiss is one of the most loved of all mountain plants. Unfortunately, it is so admired that it gets dug up and taken home as a reminder of alpine holidays. Sadly, most of these collected plants die before the journey home is completed, while the mountains are slowly becoming denuded of this marvellous plant.

The plant that is most commonly grown is the alpine edelweiss, Leontopodium alpinum. It forms a compact cushion of green leaves, covered in small white hairs, and white flowering heads. The most commonly cultivated variety is ‘Mignon’, which is one of the best at keeping its compact shape.

These plants should be grown on the top of a rock garden, where they will enjoy the best drainage. Species other than Leontopodium alpinum are probably best treated as alpine-house plants and grown in pots, where they can be protected from the wet. As far as the cold is concerned, these are completely hardy plants, but in wet areas, it is a good idea to cover them with a sheet of glass during the winter to deflect the rain. However, don’t cover them completely as it is important that there is a flow of air around the plants.

Plant out new plants in the spring but don’t plant them too deeply and place some grit or gravel under the cushion to protect the leaves from damp soil. These plants must have as much light as possible and in the main, require no watering, pruning or training.

Growing Requirements

Soil
Leontopodium alpinum need a very lean, sparse soil. Any richness in it will cause the plant to become drawn, loose and prone to attack by disease. A gritty, well-drained soil is essential to keep the plant’s compact shape, like those seen in the mountains.

Size
Edelweiss will grow to a height and width of 8in (20cm).

Propagation
Plants can be increased in the spring either by sowing seed or by dividing them.

Family: Asteraceae
Genus: Leontopodium

Despite having an almost completely unpronounceable name, Campanula poscharskyana is a very attractive and valuable plant for the rock garden. It is a vigorous, low-growing plant with long, trailing stems bearing finely toothed, rounded or heart-shaped leaves. The plants do have a tendency to become rampant, but, fortunately, they are not too difficult to cut back.

This species of campanula makes a very good ground cover plant, especially in areas where it can spread at will. If planted among low growing shrubs, it is likely to clamber up through the lower branches. It can be grown in a rock garden, but it will need checking to make sure that it does not smother its neighbours.

Plant out in the autumn, or in spring, whenever the weather allows. These plants spread rapidly and there is rarely any need for more than one plant, unless you are using them for ground cover when you should plant them about 2ft (60cm) apart. These plants are completely hardy and will survive the winter without any problems.

This species is sometimes confused with another campanula with an unpronounceable name, Campanula portenschlagiana, which has a very similar appearance, but is less invasive and has darker, less star-like flowers.

Growing Requirements

Position
This campanula is will grow in either full sun or moderate shade and in any type of garden soil. They do best in well-drained soils and in rich soils they are quite likely to become rampant. There should be no need to water them unless there is a drought.

Size
Plants will grow to a height of 10in (25cm) and spread indefinitely!

Propagation
It is usually easy to find a few rooted stems that can be potted up to produce new plants. This is best done in spring, but can be done at any other time of the year. Campanula poscharskyana is also easy to divide.

Family: Campanulaceae
Genus: Campanula

Thrift is a familiar coastal plant and it is found around all of the coasts of Britain. It makes an unusual evergreen perennial for the rock garden. It has spiky, narrow leaves that grow in mounded humps and provide distinctive form and texture, among the numerous loose growing rock plants. It is known by several common names, including thrift, sea thrift and sea pink.

As a seaside perennial, thrift is an excellent choice for maritime gardens. It is fully frost hardy, but may die off if exposed to long periods of wet and cold. With age, the centre of the plant will turn brown and eventually die off. It should then be replaced with new, young plants.

Between April and October, thrift produces a mass of pom-pom flowers on short stalks above the dark green leaves. The colour of the flowers ranges from white through to dark pink. Apart from the removal of dead flower heads, little aftercare or maintenance is required.

Growing Requirements

Position
Armeria Maritima is native to sandy soils but will happily grow in a free-draining clay soil - add plenty of grit to the planting hole. It thrives in full sun and lost be paid by the hot summer sunshine. Moisture is essential to establishment, but excess moisture will lead to rotting and eventual death. When watering in newly planted thrift, avoid wetting the top of the plant by talking the spout of the watering can, under the hum of the foliage.

Size
Thrift will grow to a height of 4in (10cm) and spread about 6in (15cm).

Propagation
Named varieties can be propagated by taking semi-ripe cuttings in summer or early autumn and growing them in sand. Thrift is easy to grow from seed. Sow seed under glass in late spring or outdoors, in June and July.

Family: Plumbaginaceae
Genus: Armeria